New confessions mean his female victims now number 69, with at least a dozen more charges expected soon, taking his macabre toll to 81.

Popkov has confessed to 59 new murders. Picture: Vostochno-Sibirskaya Pravda

Siberian maniac and former policeman Mikhail Popkov - who raped his victims before killing them - appears to be the world's third worst known serial killer.

In an interview today with The Siberian Times, the Russian Investigative Committee - the Russian equivalent of the FBI - clarified a series of confusing news agency and newspaper reports this week on the number of new cases.

The true total of women victims - believed to be aged 17 to 38 - is far higher than previously reported.

The sensational new findings follow intensive detective work over two years since father-of-one Popkov - who was married when he committed his offences and is nicknamed 'The Werewolf' - was convicted in January 2015 of an initial 22 murders of mostly young women.

Irkutsk Investigative Committee spokeswoman Karina Golovacheva: 'So there are 59 new murders. That means, if we add them to the earlier 22, it will be 81 murders in total.' Picture: Investigative Committee in Irkutsk region

The butcher sexually attacked his mainly young female victims before slaying them with axes, knives or screwdrivers over an 18 year period immediately following the collapse of the Soviet Union.

Irkutsk Investigative Committee spokeswoman Karina Golovacheva admitted there had been confusion over the numbers, and used her interview with The Siberian Times to officially clarify and confirm the sinister detail of Popkov's reign of terror.

'To clarify the numbers, Popkov has confessed to 59 new murders,' she said. 'We are not counting in this total those 22 for which he was already sentenced. These cases are already closed.

'So there are 59 new murders. That means, if we add them to the earlier 22, it will be 81 murders in total.'

Popkov (middle) has a higher total than worst-ever Soviet serial killer Andrei Chikatilo (right) who was convicted of 53 murders, and the more recent Moscow maniac Alexander Pichushkin (left), known as the Chessboard Killer, who killed 49. Picture: The Siberian Times

She said that currently he is charged with 47 new murders, and another dozen are still officially under investigation, but imminent charges are expected over these additional alleged crimes.

She emphasised: 'We are quite sure about the 12 other cases. We are now gathering all the evidence.' Further analysis of the evidence is underway and 'in the nearest future we can bring charges in these 12 cases' which Popkov has already admitted.

Earlier, contradictory reports in Russian news agencies led to conflicting reports on the numbers.

But it is today clear that Popkov - on the basis of charges to which he has already confessed - has a higher total than worst-ever Soviet serial killer Andrei Chikatilo, aka the Butcher of Rostov, who was convicted of 53 murders, and the more recent Moscow maniac Alexander Pichushkin, known as the Chessboard Killer, who killed 49.

He is also higher than Ukrainian Anatoly Onoprienko, who was active at the end of the Soviet era, and was convicted of a total of 52 murders.

'He says very clearly, when and what was done. We are looking for evidence that confirms his words. A large number of episodes are confirmed.' Picture: Investigative Committee, The Siberian Times

If - as expected following his confessions - his toll is confirmed by the court as 81, only two serial killers in the world, Luis Garavito and Pedro Lopez, both South American, will have had higher numbers of proven victims.

'When the investigation is finished, and Popkov has read the case materials, the trial can begin,' she said.

It is also now established that his murders continued for a full decade after police previously believed they had stopped. 'The period of his murders also has changed,' she said. 'He was killing women from 1992 to 2010, so he did not stop in 2000.'

Earlier, investigators believed he was correct in saying that he had halted his vicious sexual attacks and killings in 2000 because he became 'impotent' after contracting venereal disease from a victim.

Tatiana Martynova (right) with a friend Yulia Kuprikova (middle) who they were both killed together. Viktoria Chagaeva (L), pictured with her younger sister Tatiana and mother Lyubov. Viktoria Chagaeva, 49, who owns a beauty salon in Angarsk, with a picture of her beloved younger sister Tatiana, killed by the 'Wednesday murderer'. Pictures: The Siberian Times

Popkov is co-operating with investigators, and his testimony has been crucial to uncovering the 59 new cases. But it is not ruled out that there are more cases than the 81 he admits.

One theory is that he is deliberately rationing his confessions to delay the moment when he is sent from his current detention prison to a harsh penal colony to serve his life sentence.

In a court appearance in Irkutsk, details of which have just been disclosed, he was asked by judge Pavel Rukavishnikov how many women he had killed. He shrugged and replied: 'I can't say exactly, I didn't keep a record.'

But the mass killer told the court: 'I admit my guilt in full'....'committing the murders, I was guided by my inner convictions.'

After he was detained in 2012, he told police he wanted to 'cleanse' the streets of 'prostitutes'.

The maniac's victims, top to bottom - Yulia Shapovalova and Maria Molotkova; Maria Molotkova funerals, and pictures of two other victims, Marina Lyzhina, 35 (l) and Liliya Pashkovskaya, 37 (r) at their funerals. Pictures: The Siberian Times

He often offered victims nighttime lifts in his police car before taking them to remote locations where he raped and killed them, leaving their naked bodies in woods on roadsides.

Senior investigator Andrei Bunayev disclosed last year: 'The investigation will be very long because there are a lot of cases. He names the places where bodies are hidden.

'We find these bodies, and check his involvement. He says very clearly, when and what was done. We are looking for evidence that confirms his words. A large number of episodes are confirmed.'

He said Popkov 'left biological traces in some cases which were not studied earlier - but now there is an opportunity to examine them'. In other cases, sites were dug up guided by the convicted mass murderer.

Victim Yulia Kuprikova, killed by the 'Wednesday murderer'. Picture: The Siberian Times

'Popkov is collaborating with us,' he said. 'Everything he says is confirmed. He confidently guides us to the place where a body is found and explains what happened, what injuries he caused.'

After he ceased being a policeman, it is known Popkov drove between his home city of Angarsk, in Irkutsk region, where many of his crimes were committed, and Vladivostok, on the country's Pacific coast, a distance of some 3,900 kilometres.

Yet a painstaking search has not found evidence of crimes in other regions - so far.

'It was established that he killed women in other cities and towns of Irkutsk region, but we have not found any evidence he killed someone in other regions,' - said Lieutenant Golovacheva.

'At the moment we cannot give much detail as the investigation is ongoing. We can say more when the trial starts.'

Two of his earlier victims were Tatiana (Tanya) Martynova, 20, and Yulia Kuprikova, 19, found dead on 29 October 1998 in an Angarsk suburb following a night out.

One theory is that he began his murder spree after - wrongly - suspecting his wife Elena of cheating on him. Pictures: Channel 1, NTV

'The pain does not go away - it was me who gave Tanya a ticket to go to a concert, and she was killed after attending it," said her sister Viktoria Chagaeva, 49, who owns a beauty salon in Angarsk.

Popkov's wife Elena, 51, and daughter Ekaterina, 29, a teacher, initially stood by him, refusing to believe he was a mass killer. But since his trial they have moved to another city to begin new lives.

One theory is that he began his murder spree after - wrongly - suspecting his wife of cheating on him. He found two used condoms in the rubbish at home, and this led to his drive to take revenge on women, it is claimed. In fact the contraceptives had been used by guests.

'I just had some reasons to suspect her,' said Popkov, of his belief that his wife had slept with another man. 'I'm not looking for excuses, but this was the impetus for my future.'

His daughter Ekaterina, 29, a teacher, initially stood by him, refusing to believe he was a mass killer. Pictures: Channel 1, NTV

He admitted to having a negative view of women who went out at night to drink without their husbands or boyfriends. Now he says: 'I had no right to evaluate people, their behaviour ... this is my repentance.'

He evaded capture for years because police could not contemplate that one of their own officers could be a mass killer.

He daughter at first refused to believe he could be a mass killer.

'I do not believe any of this. I always felt myself as 'Daddy's girl',' she said. 'For 25 years we were together, hand in hand.

'We walked, rode bikes, went to the shops, and he met me from school. We both collect model cars, so we have the same hobby. I wanted to be a criminologist, so I read a book with tips of how investigators catch serial killers and there were also basic classifications [about murderers].

he told police he wanted to 'cleanse' the streets of 'prostitutes' in his home city of Angarsk where he worked as a policeman. Pictures: The Siberian Times, Photo-Angarsk

'Daddy doesn't fit any of these classifications -- he doesn't look like some maniac.'

Popkov has previous told journalists that he was only caught because of advances in DNA technology used to tackle crimes.

'I could not anticipate the examination of DNA,' he said. 'I was born in another century. Now there are such modern technologies, methods, but not earlier. If we have not got to that level of genetic examination, then ... I would not be sitting in front of you.'

Asked he could turn back time, what he would do differently, he said: 'All initially should have been changed. Straight from school. Since childhood.'